password protect excel file, protect excel sheet

when you password protect the excel file, you can do this for two options , one pasword for OPEN and one for MODIFY.

Protecting the File

1. From the File menu, select Save As...The Save As dialog box appears.
2. From the Tools pull-down list, select General Options...
   The General Options dialog box appears.
3.  in the Password to open text box, type a password
   in the Password to modify text box, type a password
4. OPTIONAL: If you  like Excel to recommend that this file be opened as a read-only file each time it is opened, select Read-only recommended
5. Click OKThe Confirm Password dialog box appears.
6. In the Reenter password to modify text box, type the password(s) in the order of the password(s) that you typed in the Save Options dialog box
7. Click OK
8. Click SAVE 

Unprotecting the File

If you no longer need to password-protect the file, you can remove the password.

1. Open the file
2. From the File menu, select Save As…
3. In the Save As dialog box, from the Tools pull-down list, select General Options...
4. In the Password to open text box, select the text » press [Delete]
5. In the Password to modify text box, select the text » press [Delete]
6. Click OKThe file is no longer password protected.
7. To save the file, click SAVE 
8. Click YES